Page 81, question number 31 A

V=square root

31. The area of a triangle can be determined using Heron's formula, which requires the side lengths of the triangle. Heron's formula is A=Vs(s-a)(s-b)(s-c). In the formula A is the area; a, b, and c are the side lengths; and s is half the perimeter or a+b+c/2.

     
Determine the area of each triangle with the following side lengths. Express each area to the nearest tenth of a square centimeter. 
A) 15cm, 12cm, 10cm
B) 9.3cm, 11.4cm, 7.5cm

A= Vs(s-a)(s-b)(s-c)
A= Area
a, b, c= side lengths 
S= Half of the perimeter 

15+12+10=37
=37/2
=18.5

 V 18.5(18.5-15)(18.5-12)(18.5-10)

 V 18.5(3.5)(6.5)(8.5) V 18.5(22.75)(8.5) V 18.5(193.375) V 3577.4375 =59.81168364If you round off 59.81168364 to the nearest tenth, it would be 59.8cm.


A) 15cm, 12cm, 10cm is the right answer.

Textbook problem #33 page 81

Textbook pg.79, #15

             

     15. Kai needs to replace the strip of laminate that is glued to the vertical faces on a square tabletop. The tabletop has an area of 1.69m². What length does she need?

            Solution: 

                Explanation:    We are squaring the area of the tabletop because we are trying to find which factors are equivalents to 1.69m² and those factors are the side length of the tabletop.

                ANSWER:  Kai needs 1.3m laminate.

                       

Textbook Pg. 62 #25

25. create a word problem that involves operations with rational numbers in decimal form. Make sure you can solve your problem. Then, have a classmate solve your problem

If 3 pizzas were cut into 8.5 slices per pizza then 2.145 slices were eaten but 0.503 of a slice was left over with 2 extra pizzas that was ordered recently, how many pizza slices are there left?







Answer:  3*8.5-2.145+0.503+8.5*2 = 25.5-2.145+0.503+17
                                                         = 40.858


There would be 40.858 slices of pizza left

Textbook page 68 #9

 

Question: Lori owed her mother $39. Lori paid back 1/3 of this debt and then paid back 1/4 of the remaining debt.
How Much does Lori still owe her mother?

$39 / 3=$13

$39 - $13=$26

$26 / 4=$3.25

$26 - $3.25=$22.75

Lori still owes her mother $22.75

Textbook pg 62 number 29

Textbook, Page 62, Question# 29
 Kim Gacusan 9-06

**** Hello Mr. Backe!  I found the square brackets!! yay!haha -Kim :)

Textbook pg.62 #27

Textbook, Page 62, Question# 27

Daphne A. 9-06